The jump from 8800 GTX (my previous Card) to GTX 2xx Series was substantial indeed......I believe that SLI during the 8000 Series was pretty "green" and "immature".....going back to the 7000 Series I'm sure they were still trying to figure out optimized Drivers....
Still... Tri Sli 8800 Ultras is Uber Performance indeed.
I'd love to see a comparison of your rig on this I7 Tri Sli Gtx 280 Rig, just for fun...
If you can run the FC2 Benchmark Short Ranch 1920 x 1200 Ultra Settings 8xAA - 3 Loops...would be very curious to see the results!